<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, inigectial-scale=1.0">
    <title>Document</title>
</head>

<body>

    <script>
        var a = 123;
        var b = '123';
        var str = 'Hello World';
        var array = str.split(' ');
        alert(array[1]);
        alert(b.toUpperCase())
        alert(a == b);
        alert(a === b);
    </script>

</body>

</html>